Frost indicator for refrigerators



NOV. 25, 1952 R. J C RB R FROST INDICATOR FOR REFRIGERATORS 2 SHEETS-SHEET l w a b P a C llw d P a h .m R

Wm %M 6 AH Filed Dec. 21 1950 NOV. 25, 1952 ARB R FROST INDICATOR FOR REFRIGERATORS 2 Sl-lEETS-SHEET 2 illkmfi a. .n .b r C. W05 m U 4 5 Wm m m w w Filed Dec. 21, 1950 Patented Nov. 25, 1.952

"FROST INDICATOR FOR REFRIGERATORS .Riclrar'd lzcarbaryflErie, Pa., assiglior to General Electric c'ompanyrincorporation of New .York

ApplicationlDe'c'ember""21, 1950,"SeriZiPNmZMfQH 37 'iClaims. (Cl. 116- 114") My "invention relates "to refrigerators and more particularly to frost indicators for refrigerator evapora'tors.

In many household refrigerators the food s'torage compartment is cooled by an evaporator whose surface -i-s exposed to the air in the compartment. Consequently, moisture condenses from the air on the siibs't-an'tially cooler surface of the -evaporator and "collects thereon ==as frost. '--In order to maintain a "satisfactory e'inciency of the refrigerating apparatus, it is "necessary "to "remove this frost from time to time, and hence it is desirable to call the user's "attention to the thickness "of frost collected there- I on and particiilarly to-call his-attention "t0 the presence on the evaporator or frost of -'a :predetermined maximum thickness. In "connection with horizontal, or fdll widthpevaporators which extend substantially the full Widl'ih'bf the food storage compartment -and are covered -by the evaporator door, it is difficult for "the user to determine the amount of' fros't -col1ected on "the evaporator and hence easy for him to overlook the necessity for defrosting. Moreover, with this type of evaporator, the thickest blanket "of frost usually collects on the rear wall of the evaporator where it is oompletly concealed' from the users view. By my invention I have provided an arrangement which olearly indicates to the-user the thickn'ess of rro's't collected "on the evaporator a-nd more particularly indicates the thickness of fro'st-on' the otherwiseconcealed rear wall of the evaporator. Moreover, the-"indicator is positioned so 'as to minimize the -danger that the need for defrosting-may be-"overlooked by the us'er.

It is an object-of invention to'provide an improved arrangement for -indicating a thickness of frost on -'a refrigerator evaporator.

leis-another object of my invention'to provide an improved arrangement for indicating the thickness :of frost on a refrigerator evaporator each time the evaporator d'00r ts opened.

vIt is another object of my invention to provide 'an improved :irost indicating "arrangement partimilarly adapted lfor 'full width evapordtors and including an -='el'em'ent engaging the frost each time "the evaporator door is --opene'd to indicate the thickness of :frost.

Further zobjects and advantages o'f m'y inven tion 'will become apparent :as the l-i'ollowin'g oesoription proceeds and the features of novl ty which =characterizeimy invention zwil i'fije pointed out with particularity in the claims annexed' to and forming "a ipart of this specification.

In carrying out the objects of my invention,

I provide a slidable member ipositioned between the side wall of the *e'vaporat'or and the s'ide wail of the liner forming "the food s'torage -'compartmen't. *This member includes a laterallly-ieiiterid ing element adapted to engage the f-ros't on the rear wall of the evaporator, and the men'iber' is biased forwardly by a spring so as to bring this element into engagement with the trost; spring assembly is provided for bia's'ing the evaporator door to i-ts closed position and'this spring assembly :is arranged to engage the slidable member fo'r moving the frost-eng'ag ing element away from the frost =w-hen the evaporator door is in its closed position. A r'otatable tabular indicating --lement .is arranged at the terward portion of "the compartment and :an elongated opening in this element is engaged by a spiral strip provided on the forward en'd o'f theeslidable memberis'o that movement of the slidable member is efiective for rritating t'he indicating element by an amount depending upon the amokness of the frost aon the eva orator. suitable indicia 'are provided for indicating the thick ness of ifrost :or at least for =indicating when an abnormal amount of fros't has collected i019. th'e evaporator.

For a better understanding of :my invention, reference may behadto the'accompanying drawings in which Fig. 1 is a' vi'ew of a poi 'tion of a refrigerator cabin'et illustrating an embodiment of my invention; Fig- 2 is a pl'an vieve-stroveing details of my invention; Fig. 3..is armadavation view of the --me'ch'anism illustrated f in Eig. 2; Fig. 4 is an enlarged view of the indiealriing element and its mounting; *Fig. his a manholevation taken along the vline 5: 5 .Lin 1; 6 is .a :sectional view taken along zthe i6=.6 in Fig. 4; and Fig. '7 is a View taken along the line 1'|.in.Fig.-'3.

Referring to Fig. 1, thereisshown'a refrigerator l including an inner .liner 2 .ior defining a food storage compartment '3. The :iood storage compartmentis cooled byan evaporator '4 which is of the horizontal, or fiill width type, xtending substantially the "ftill Width of the food storage compartment 3. "The access opening .ofthe evaporator '4 is closed by a door 5. The-door 5 is hinged, as indicated a' tfiyformovement about a horizontal axis. During normal opera'tion, since the evaporator 4 is exposed to the air "in the food storage -compartment :3, moisture from .the air condenses on the substantially cooler walls of the evaporator :and acollects -thereon' on :the form of irost. This frost may eventually reach a thickness suflicient to reduce materially the effectiveness of the evaporator. The frost build-up is particularly large along the rear wall of the evaporator. In order to indicate to the user the thickness of frost collected on the evaporator and particularly the relatively large thickness of frost which may collect on the concealed rear wall, an indicating arrangement illustrated in Figs. 2 and 3 is provided. This indicating arrangement includes a slidable member I, which is disposed between the side wall 8 of the evaporator and the side wall 9 of the liner 2. This slidable member 1 includes a laterally extending portion or element I3 which is adapted to engage the frost on the rear wall ll of the evaporator. The frost-engaging element ID is formed of a generally U-shaped portion of the slidable member 1 so as to provide a relatively large area of contact with the frost, thereby minimizing the penetration of the frost by the frost-engagingelement.

{For slidably supporting the rear portion of the slidable member 1, a support I2 is provided at'the rear portion of the side wall of the liner 2. This support 12 is secured to the side wall 9 by bolts I 3 or other suitable fastening devices. The support I2 includes a slot or opening l4 within which-the member I is slidably received. The rear portion of the member 7 is formed to include two parallel rods l5 and I6, both of which are received in spaced relationship within the opening l4. Details of th construction of the support I2 and of the mounting of the slidable member 7 therein are shown in Fig. '7. The broad idea of a frost indicator which includes a slidable member mounted adjacent the evaporator and having an element biased toward the frost on the evaporator and which includes means for connecting the slidable member and a directly visible rotatable indicating element for effecting rotation of the indicating element in accordance with the sliding movement of the member is not claimed in the present application but is described and claimed in my application Serial No. D. 88,047, filed concurrently with the present application and assigned to the same assignee.

At the forward portion of the compartment 3, there is provided a rotatable cylindrical indicating element [1. The indicating element I1 is rotatably mounted on a front support 18 which is secured to the front portion of the side wall 9 of the liner by screws l9 or other suitable fastening devices passing through-openings [9a. The support or bracket [8 is U-shaped, including spaced parallelsections and 2|. The sections 20 and 2| include openings 22 and 23, respectively, within which the indicating element 11 is rotatably mounted.

Details of construction of the indicating element l1 and the support 18 are shown in Figs. 4, 5 and 6. As there illustrated, the indicating element [1 includes a front cap or disc 24, a rear cap or disc 25, and an intermediate generally tubular section 26. The generally tubular intermediate section 26 is formed by two elongated spaced members 21 and 28 which are secured at their ends to the caps 24 and 25 and provide therebetween a space 29 for receiving the forward end of the slidable member 1. The indicating element I1 is held in fixed axial position with respect to the support l8 by a snap ring 30 received within a groove 30a in the cap 24. This ring 30 engages one face of the section 20 of the support l8 and a shoulder 3| formed on the cap 24 engages the opposite face.

In order to provide for rotation of the indicating element ll coincident with horizontal or sliding longitudinal movement of the sliding member 1, the indicating element l1, and specifically its rear cap 25, is provided with an elongated opening 32 for receiving the forward end 33 of the slidable member 1, and this forward end 33 is twisted, as indicated at 34, into spiral form. Thus relative longitudinal movement between the slidable member I and the cap 25 of the indicating element I! effects, through engagement of the spiral section or strip 34 with the elongated opening 32 a rotation of the indicating element H. To minimize binding of the spiral strip 34 in the opening 32, the sides of the opening 32 are curved, as shown in Fig. 6. This relationship is employed for positioning the indicating element I! so as to indicate to the user the frost condition on the evaporator. As mentioned pre viously, the laterally extending portion [0 of the slidable member 1 is arranged to engage the frost on the rear wall ll of the evaporator, and the slidable member 1 is biased forwardly by a spring 35 to a position wherein the element l0 engages the frost. The spring 35 surrounds a portion of the rod [5 of the slidable member 1; one end of the spring engages a vertical leg 36 of the slidable member I and the other end engages the rear support l2, this latter end being received within a recess 31 in the rear support for assisting in positioning the spring. The amount of forward movement of the slidable member 1 under the bias of the spring 35, and hence the ultimate position of the rotatabl indicating element H, is determined by the thickness of the frost on the rear wall of the evaporator.

The evaporator door 5 is biased to the closed position illustrated by a spring assembly 38. This spring assembly 38 includes arm 39 having an opening '40 for receiving a'pin 4| secured to the door 5 and a hook 42 received within an opening 43 in a bracket 44 secured by bolts 45 or other suitable fastening devices to the side wall of the liner. The spring assembly 38 further includes a spring 45 connected at its ends to the arm 39 in the hook 42.

The spring assembly 38 is utilized for maintaining the slidable member 1 in a rearward position wherein the frost-engaging element I0 is spaced from the frost on the rear wall of the evaporator whenever the evaporator door 5 is in its closed position. To effect this positioning of the slidable member I, the spring assembly 38 further includes an upwardly extending element 47, and the slidable member 1 includes a cooperating depending element 48. As illustrated, for example, by the solid line position in Fig. 3, when the door 5 is in its closed position the depending element 48 is engaged by the upwardly extending element 4'! and the slidable member I is held in a rearward position against the bias of the spring 35. The spring 46 is substantially stronger than the spring 35 and easily overcomes the bias of the spring 35. Whenever the evaporator door 5 is opened, the upwardly extending element 41 is moved forwardly to the dotted line position indicated at 49 out of engagement with the depending element 48, and under this condition the spring 35 moves the slidable member 7 forwardly. The amount of the forward movement 'of the slidable member 1 is dependent uponithe' thickness of the frost on the rear wall H of the evaporator, since the for-ward movement of the slid-able member 1 is limited by the engagement of "the laterally extending portion H] with the frost on the rear wall. The amountof the forward movement of theslidable member -1 in turn, through the actuation'of the indicating element H by the spiral portion of the slidable'member 1, determines the amount-of rotation *of the indicating element H. "Suitable indicia'are provided for utilizing this rotation of the indicatingelement H to "in- -di'cateto the 'user the thickness of -frost:on the rear "wall of the evaporator. As shown in Fig. 5, the-section 20 of the support I8 is "provided adjacent the opening 22 therein with suitable legends, for exam'ple DEF for indicating need for -defrosting and Normal for indicating a thickness of'frost below "the predetermined maximumat which "defrosting is essential. The indi'c'atinjg element 11 is'provided with apointertli arranged upon rotation of the indicatingelem'ent H "to point to various portions of "the legend on the section 720 or the support Hi. This .poin'ter 50 "may, asindicated in Fig. 4,'be'provided on "a metal disc 5| securedto the front of the capiZ'.

For providing a finished appearance, a filler strip 52 of plastic or other suitable material is disposedbetween theside wall 8 of the evaporator and the side wall 9 of the liner. This filler strip 5'2iis secured to a "flange 53 on thefront of the evaporator by screws or other suitable fastening devices .(not shown) and a gasket 5 adapted to be engaged .by the door "5 overlaps the inner edge of theffiller strip '52. The filler strip 52 'includes an opening 55for receiving the indicating element "Ill and the section 263 of the support It and with a second opening 56 through which the arm 39 of the-spring assembly 38 passes.

The operation .of the frost indicating .rnechanismis as follows. When the door 5 is in its closed position, as biased by the springassembly 38, the upwardly extending element 41 engages the-depending element 48 and moves the slidable member 1 to the-rearward position indicated by solid lines wherein the frost-engaging portion it thereof is spaced from the frost on the rear wall H --of the evaporator. Whenever the evaporator ,door5 ismoved to itsopen position, the upwardly extending .element 41 moves away from the depending element 43 allowing the bias exerted by the spring .35 to effect a forward movement of the slidable member 1. The amount .of this forward movement is determined by the thick- -ness-of the frost on the rear wallof the evapnrator'and by the engagement of the element it therewith. During forward longitudinal movement of the slidable member I, the indicating .element .[1 is .rotated because of the relative movement between the spiral section 34 of the slidable member and the elongated opening 32 in the disc 25 of the indicating element H. The amount of rotation is, of course, determined by the amount of the longitudinal movement of the slidable member I and hence the final position of the indicating element H and of the pointer 50 thereon is determined by the thickness of frost on the evaporator. Thus, where there is substantially no frost on the evaporator and when the slidable member 1 moves to the dotted line position indicated in Figs. 2 and 3, there is substantial clockwise rotation of the indicating element, as viewed from the front end thereof, effected by the spiral section 34 and the indicating element occupies an ultimate position shown in Fig. 5 wherein the pointer 50 is directed well down in the normal range, indicating little or no frost on the evaporator. As the frost builds up on the rear wall of'the evaporator and hence as the forward movement-of the slidable member is limitedto a lesser-"amount than that indicated by the dotted line-position'in Fig. 3, there is a smaller clockwise movement of the indicating element 11 and the pointer 55! will occupy a-position approaching moreclosely to 'the defrosting range'indicated by'th'e legend on the section 20 of the support 18. Ultimately when the'thickness of frost hasreached a =predetermined maximum at which-defrosting is con- 'sidered essential, there will be little forward movement of the slidable member 1 and hence little clockwise rotation of the indicating element I! and the pointer 50 will point'to the area indicated by DEF, thereby indicating "the need for defrosting. As an alternative to the'defrost and'normal legends illustrated, it will beappreciated that the section 20 of the support i8 could be marked with graduationswhereby-the pointer would indicate directly the thickness of frost on the rear wall of the evaporator.

While I have shown and described a specific embodiment of my invention, I do not desire my invention to be limited to the particular construction shown and describedand I intend by the ap pended claims to 'cover-allmodifications within the spirit and scope of my invention.

What I claim .as new and desire 'to "secure by Letters Patent of the United States is:

l. A refrigerator comprising a liner defining "a food storage compartment, an evaporator upon which frost collects disposed in said compartment, a slidable member mounted adjacent said evaporator, saidmember including an element for engaging the frost collected onsaid evaporator, meansfor biasing said member toward a position where said eiement engages said frost, a rotatable indicating element mounted at the forward portion of said compartment, said indicating element having an opening of elongated cross section therein, said member including a spiral strip at its forward end received in said opening whereby sliding movement of said member effects rotation of said indicating element, and means for normally maintaining said frost-engaging element spaced from said frost against the bias of said biasin means.

2. A refrigerator comprising aliner defining a food storage compartment, an evaporator upon which frost collects disposed in said compartment, a slidable membermounted adjacentsaid evaporator, said. member including an element for engaging the frost collected on said evaporator, means for biasing said member toward a position where said element engages said frost, a rotatable indicating element mounted at the forward portion of said compartment, said element including an elongated tubular section, a first cap secured to one end of said tubular section and having an opening of elongated cross section therein, a second cap secured to the other end of said tubular section and having an indicatin pointer thereon, said member including a spiral strip at its forward end received in said opening in said first cap whereby sliding movement of said member effects rotation of said indicating element, and means for normally maintaining said frost-engaging element spaced from said frost against the bias of said biasing means.

3. A refrigerator comprising a liner defining a food storoge compartment, said liner including a side wall and a rear wall, an evaporator upon which frost collects disposed in said compartment,

said evaporator including a side wall spaced from the side wall of said liner and a rear wall spaced from the rear wall of said liner, a slidable member disposed in the space between said side walls of said evaporator and said liner, said member including a laterally extending portion adapted to engage frost collected on said rear wall of said evaporator, means for biasing said member forwardly to a position where said laterally extending portion engages said frost, a rotatable indicating element mounted at the forward portion of said compartment, said indicating element having an opening of elongated cross section therein, said member including a spiral strip at its forward end received in said opening whereby slidin movement of said member effects rotation of said indicating element, and means for normally maintaining said frost-engaging element spaced from said frost against the bias of said biasing means.

4. A refrigerator comprising a liner defining a food storage compartment, an evaporator upon which frost collects disposed in said compartment, a slidable member mounted adjacent said evaporator, said member including an element for engaging the frost collected on said evaporator, means for biasing said member toward a position where said element engages said frost, a rotatable indicating element mounted on the forward portion of said compartment, said indicating element having an opening of elongated cross section therein, said member including a spiral strip at its forward end received in said openin whereby sliding movement of said member effects rotation of said indicating element, a door for said evaporator, and a spring assembly for biasing said door to its closed position, said spring assembly engaging said slidable member for moving said frostengaging element away from said frost when said evaporator door is moved to its closed position.

5. A refrigerator comprising a liner defining a food storage compartment, said liner including a side wall and a rear wall, an evaporator upon which frost collects disposed in said compartment, said evaporator including a side wall spaced from the side wall of said liner and a rear wall spaced from the rear wall of said liner, a front support secured to the front portion of said side wall of said liner, a rear support secured to the rear portion of said side wall of said liner, a slidable member mounted on said rear support, an indicatin element rotatably mounted on said front support, said slidable member including a laterally extending portion adapted to engage frost collected on said rear Wall of said evaporator, a spring engaging said rear support and said member for biasing said member forwardly to a position where said laterally extending portion engages said frost, said indicating element having an opening of elongated cross section therein, said member including a spiral strip at its forward end received in said opening whereby slidin movement of said member effects rotation of said indicating element, and means for normally maintaining said frost-engaging element spaced from said frost against the bias of said biasing means.

6. A refrigerator, comprising a liner defining a food storage compartment, an evaporator upon which frost collects disposed in said compartment, a slidable member mounted adjacent said evaporator, said member including an element for engaging the frost collected on said evaporator, means for biasing said member toward a position where said element engages said frost, a rotatable indicating element mounted on the forward portion of said compartment, said indicating element having an opening of elongated cross section therein, said member including a spiral strip at its forward end received in said opening whereby sliding movement of said member effects rotation of said indicating element, a door for said evaporator, and a spring assembly for biasing said door to its closed position, said slidable member including a depending element, said spring assembly including an upwardly extending element for engaging said depending element to move said frost-engaging element of said slidable member away from said frost when said evaporator door is in its closed position.

7. A refrigerator comprising a liner defining a food storage compartment, said liner including a side wall and a rear wall, an evaporator upon which frost collects disposed in said compartment, said evaporator extending substantially the full width of said storage compartment and including a side wall spaced from the side wall of said liner and a rear wall spaced from the rear wall of said liner, a slidable member disposed in the space between said side walls of said evaporator and said liner, said member including a laterally extending portion adapted to engage frost collected on said rear wall of said evaporator, means for biasing said member forwardly to a position where said laterally extending portion engages said frost, a filler strip between said side wall of said evaporator and said side wall of said liner, said filler strip having an opening therein, a rotatable indicating element mounted at the forward portion of said compartment and extending through said opening in said filler strip, said indicating element having an opening of elongated cross section therein, said slidable member including a spiral strip at its forward end received in said opening whereby sliding movement of said member effects rotation of said indicating element, said indicating element including a pointer on its front face, means adjacent said opening having indicia thereon whereby the position of said pointer indicates the frost condition on said rear wall of said evaporator, and means for normally maintaining said frost-engaging element spaced from said frost against the bias of said biasing means.

RICHARD J. CARBARY.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,371,395 Rast Mar. 15, 1921 2,112,261 Backstrom Mar. 29, 1938 

